The studies supported by this grant are aimed at learning how cytochrome P-450 works and the effect of cytochrome b5 on the enzyme function. Cytochrome P-450 physical parameters and measured and quantitated and the significance to function have been reported (Gibson, et al., J. Biol. Chem. 255, 1867 - 1873 (1980), Sligar, et al., Biochem. Biophys. Res. Comm. 90, 925 - 932 (1979)).